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Subject: Re: White to move and win

Author: John Merlino

Date: 11:03:30 04/24/02

Go up one level in this thread


On April 24, 2002 at 13:48:12, Roy Eassa wrote:

>
>Does ANY program see the whole line (3 underpromotions) up front?
>
>[d] 1b6/4P3/1P2PN2/8/8/P1k5/P1p2P2/K5B1 w - - 0 1
>
>1.Ne4+
>
>   [1.Nd5+? Kd2 2.Kb2 c1Q+ 3.Kb3 Bd6! 4.Nb4 Bxe7 5.b7 Qc7 -+]
>
>1...Kd3 2.Nc5+
>
>   [2.Kb2? Be5+ and Black mates]
>
>2...Kc3 3.Nb3 Be5 4.f4! forced
>
>   [4.Bh2? Bf6 5.e8N Bh8 and Black mates!]
>
>4...Bf6 {or ...Bg7} 5.e8N! forced
>
>5...Bh8 6.f5! forced
>
>6...Be5 7.Bh2! forced
>
>7...Bxh2 8.b7! forced
>
>8...Be5! 9.b8B!
>
>   [9.b8Q? Kc4+ 10.Qxe5 c1Q+ 11.Nxc1 stalemate]
>
>9...Bxb8 10.Nc7! forced
>
>10...Bxc7 11.e7 forced
>
>11...Be5 12.e8R!
>
>   [12.e8Q? Kc4+ 13.Qxe5 c1Q+ 14.Nxc1 stalemate]
>
>12...Bg7 {or ...Bf6}
>
>13.Re6 followed by f6
>
>
>Problem attributed to Mark Libiurkin, circa 1933.

There is a problem with the above line. Here is CM's analysis from the initial
position (note the first seven moves agree with your above line):

Time	Depth	Score	Positions	Moves
0:00	2/3	9.94	3081		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Kc4
					4.Kb2
0:00	3/4	7.65	6474		1.Ne4+ Kd3 2.Nc5+ Kd2 3.Nb3+ Kd1
					4.f4 Bxf4 5.Bd4
0:00	4/5	9.82	13420		1.Ne4+ Kd3 2.Nc5+ Ke2 3.Kb2 Kd1
					4.Nd3 Be5+ 5.Kb3
0:00	5/6	12.01	27685		1.Ne4+ Kd3 2.Nc5+ Kd2 3.Nb3+ Kd1
					4.f4 Bxf4 5.Bd4 Be3 6.Bxe3
0:00	6/7	12.07	55694		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.Bh2 Bf6 5.e8=N Be7 6.Be5+ Kc4
0:01	7/8	12.01	105397		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.f4 Bf6 5.e8=N Bh8 6.f5
0:02	8/9	12.23	199081		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.f6
0:05	9/10	9.27	469863		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bd4+
					Bxd4
0:09	10/11	9.37	865339		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bh2
					Bxh2 8.Nf6
0:21	11/12	9.37	1872831		1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
					4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bh2
					Bxh2 8.Nf6

However, in your line, 8...Be5 loses outright. Here is Chessmaster 9000's
analysis after 8.b7, which says that 8...Kd3 is the best move, and leads to a
game where White has a queen and three pawns, and Black has a queen and a
bishop:

Time	Depth	Score	Positions	Moves
0:00	2/3	7.65	917		8...Be5 9.b8=Q Bxb8
0:00	3/4	7.61	2731		8...Be5 9.b8=B Bxb8 10.f6
0:00	4/5	7.73	7396		8...Be5 9.b8=B Bxb8 10.f6 Bf4
0:00	4/5	6.00	9191		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nf6
0:00	5/6	5.44	12675		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nf6 Kd2
0:00	6/7	4.47	21350		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.f6 Kb1 13.f7 c1=Q
					14.f8=Q Qc3+ 15.Ka4 Kxa2
0:00	7/8	3.61	40916		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nf6 Kb1 13.b8=Q Bxb8
0:00	8/9	2.92	71437		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.b8=Q Bxb8 13.f6
					Kb1 14.f7 c1=Q 15.f8=Q Qc2+ 16.Kb4
					Kxa2
0:01	9/10	2.91	129596		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.f6 Kb1 13.f7 c1=Q
					14.f8=Q Qc3+ 15.Ka4 Qc6+ 16.Kb4
					Qxb7+ 17.Kc5 Kxa2
0:03	10/11	2.62	316378		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nc7 Bxc7 13.b8=Q
					Bxb8 14.e7 Kd1 15.e8=Q c1=Q 16.Qxb8
					Qc2+ 17.Kb4 Qxf5
0:07	11/12	2.28	637636		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kb1
					14.e8=Q c1=Q 15.Qe2 Ka1 16.Qg2
					Qb1+ 17.Kc3
0:15	12/13	2.27	1366434		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kb1
					14.e8=Q c1=Q 15.Qe4+ Ka1 16.Qd4+
					Kb1 17.Qd3+ Ka1 18.Qc3+ Qxc3+ 19.Kxc3
					Kxa2 20.a4 Ka3
0:42	13/14	2.35	3685053		8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kd2
					14.e8=Q c1=Q 15.Qd7+ Ke3 16.Qd5
					Kf4 17.f6 Qe3+ 18.Kc4 Qc1+ 19.Kb5
					Qxa3
1:57	14/15	2.40	10277553	8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
					11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kd2
					14.e8=Q c1=Q 15.Qd7+ Ke3 16.Qd5
					Kf4 17.f6 Qe3+ 18.Kc4 Qxa3 19.Qd2+
					Kf3

Here is the analysis after 8...Be5 (note the remaining two underpromotions and
the much higher eval for White):

Time	Depth	Score	Positions	Moves
0:00	2/3	0.00	453		9.b8=Q Kc4+ 10.Qxe5 c1=Q+ 11.Nxc1
0:00	2/3	7.61	680		9.b8=B Bxb8 10.f6
0:00	3/4	7.73	1862		9.b8=B Bxb8 10.f6 Bf4
0:00	4/5	7.47	5160		9.b8=B Bxb8 10.Nf6 Be5 11.Nd7
0:00	5/6	7.92	9869		9.b8=B Bxb8 10.Nc7 Kc4 11.e7 Ba7
					12.Kb2
0:00	6/7	10.09	16706		9.b8=B Bxb8 10.Nc7 Kc4 11.e7 Ba7
					12.Kb2 c1=Q+ 13.Kxc1
0:00	7/8	6.96	31443		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re7
0:00	8/9	7.32	47963		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Rg8 Bf6
0:00	9/10	7.73	82525		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bf6 13.Re6 Bg7 14.Rc6+
					Kd3+ 15.f6
0:01	10/11	7.82	147748		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 Kd3+ 14.f6 Bf8
					15.Kb2
0:02	11/12	8.16	271525		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
					15.Kb2 Kd5 16.Re8 c1=Q+ 17.Kxc1
					Bxf6
0:04	12/13	8.20	479706		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
					15.Rd6 Kb5 16.Kb2
0:09	13/14	8.44	924526		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
					15.Rd6 Kc3 16.Rc6+ Kd3 17.Kb2
0:19	14/15	9.24	1948702		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 c1=Q+ 14.Nxc1
					Kc2+ 15.f6 Bxf6+ 16.Rxf6 Kxc1 17.a4
					Kc2 18.a5 Kd2 19.Kb2 Kd3 20.a6
0:53	15/16	9.80	5290251		9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
					12.e8=R Bg7 13.Re6 Bf8 14.Rc6+
					Kd3 15.Kb2 Ke4 16.f6 Ke5 17.f7
					c1=Q+ 18.Rxc1

jm



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